provision-single-role doesn't work

[ph1l]

elektron@x61s:~/code/marinepi-provisioning$ ./provision-single-role.sh grafana marinepi
#!/bin/bash -evx
# set role path in ansible.cfg or ANSIBLE_ROLES_PATH environment variable

role=$1
+ role=grafana

shift 1
+ shift 1

cat > /tmp/play.yml <<PLAYBOOK
---
- hosts: all
  roles:
  - $role
PLAYBOOK
+ cat

ansible-playbook /tmp/play.yml -i $1, -u pi
+ ansible-playbook /tmp/play.yml -i marinepi, -u pi
ERROR! the role 'grafana' was not found in /tmp/roles:/etc/ansible/roles:/tmp

The error appears to have been in '/tmp/play.yml': line 4, column 5, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

  roles:
  - grafana
    ^ here